As a result of the increased usage of built-in appliances, such as dishwashers, compactors, surface mounting cooking units, and other appliances built into cabinet counters, the area of the counter has been gradually reduced over the years. To further complicate the situation, the cabinet counter into which the sink was installed, prior to the occurence of plywood and particleboard, was from 26 to 27 inches in depth. However, as plywood and particleboard have now become the common cabinet materials in use today, and are manufactured in 48 inch widths, it is common practice of cabinet makers to rip each 48 inch sheet into two strips 24 inches in width to serve as cabinet counters. From this cabinet counter of 24 inches width must be deducted 3/4 of an inch for the cabinet front thickness, 3/4 of an inch for the cabinet overhang, and at times 3/4 of an inch for the cabinet counter back splash. The remaining surface depth of the cabinet counter available for installation of a sink, commonly 21 inches in width, is 213/4 inches.
As a result of the diminshed counter top area, it has become increasingly difficult to install and tighten known clamps which require a counter underside to bear against. Furthermore, the prior art sink rim clamps are designed only to accommodate a cabinet counter thickness of 3/4 of an inch. It is, however, not uncommon to encounter a cabinet counter 11/2 inches in thickness at the points where the rim clamps are to be installed. As a result of the above stated inconveniences the installer must oftimes chisel notches into the cabinet front and sides, as well as into the underside of the cabinet counter to facilitate the installation of rim securing clamps utilized in prior art installation procedures thus increasing the cost of sink installation. Also proximity of cabinet partitions and front to the counter openings is often such that the installer is unable to attach and secure the clamps to the counter underside.